1. Field of the Invention The present invention relates to an apparatus used for packing coniferous trees.
2. The Prior Art
Apparatuses of this kind are used in particular to pack conifers that are used during the Christmas period predominantly as Christmas trees and to do so either in the forest or where they are felled, so that they take up as little room as possible and can be transported without suffering any damage. It has been found that the closer the branches can be pressed against the stem or trunk, the safer the transport will be and the smaller the amount of space that will be taken up by the trees.
In a known apparatus (DE-OS No. 32 42 912.6) a frame which can be towed behind a vehicle is provided, at one end of which there is a funnel device with a mesh tube and at the other end a gripper that can be moved on the frame in a guideway towards the funnel device. This gripper has a scissors joint with gripper jaws at one end, with the gripper being connected to a retainer rod and a tube that can be slid on this at the other end. The tube is acted on by a spring that rests against the retainer plate located at one end and can also slide on the retaining rod so that when the tube is moved the gripper jaws are either opened or pressed against the trunk of the tree by the action of the scissors joint. A hydraulic cylinder is used to move the tube. This hydraulic cylinder entails considerable investment and subsequent operating costs because of the hydraulic lines and control valves that are required. A further disadvantage lies in the fact that the opening and closing gripper or gripper jaws can get caught in the net that is pulled over the mesh tube and can pull this into the funnel with it as it is moved forward, this leading to a considerable consumption of net, quite apart from the fact that it is no longer possible to grip the tree easily. In principle, the same problems occur in the apparatus that is described in U.S. Pat. No. 3,440,954 in which the gripper jaws are always held in the closed position by a spring that exerts the force required to do this. In order to introduce the trunk of a Christmas tree, one or several operating personnel must force the trunk between the jaws, i.e., must open these jaws against the force of the spring. Also insufficient is the holding force with which the spring presses the two gripper jaws against each other so that proper manipulation, i.e., the passage of the Christmas tree through the funnel, cannot be guaranteed.
It is the task of the present invention to create a gripper for packing apparatuses used to pack Christmas trees, this being to a very large extent independent of any external intervention and which works in a reliable manner and which, in addition, is easy to operate and ensures that the Christmas tree is also passed through the funnel in the proper manner.